What is a solar fountain?
Solar Power Vocabulary
Solar energy: energy given off by the sun in the form of light and heat
Direct solar energy: energy obtained directly from the sun, can be active or
passive
Active solar energy: energy obtained from a system which makes use of a
technological device, such as a photovoltaic cell
Passive solar energy: energy obtained from a system which uses only devices
that are normally part of a building, such as windows
Solar cell / photovoltaic cell (PV cell): a device that converts sunlight directly
into electricity. Most are 'sandwiches' of thin layers of silicon and metal which allow
electrons to flow freely across the layers. This flow is electric current, and can be used
to do work.
Solar panel: a panel made up of dark materials for collection of solar energy
(sunlight)
Background information
Solar cells were first used on a large scale in 1959 to provide energy aboard the U.S. space ship Vanguard 1. Since then, solar energy has been used on several other missions in space, and in various applications on Earth. Many advancements in solar energy technology have been made, but PV cells remain largely inefficient. A single PV cell only generates a small amount of energy. Several linked cells are required to provide sufficient energy for most purposes. PV cells are also quite expensive. In 1959, solar energy cost about $500.00 per watt. Currently solar energy costs almost $6.00 per watt. However, due to the inefficiency of solar energy, the cost would need to be lowered to $1.00 per watt to compete with the efficiency of fossil fuels.
In space the sun generates 3.94 x 1 0^23 kW of power all day, everyday through nuclear fusion. Of all the energy generated, almost 80,000 x 10 12 W reach the earth's surface 10,000 times the current global energy demand. As this energy heats the earth's surface, it causes air to move around the planet, generating global winds. (Thus making wind energy an indirect form of solar energy.) Fourfifths of the solar energy reaching the earth's surface falls on the oceans, driving the water cycle. The remaining fifth of the solar energy which falls on land is still 2,000 times greater than the global energy demand, making solar energy a valuable renewable resource.
Lesson What is a solar fountain?
Focus: Solar energy
Objective:
· Students will gain understanding of the nature of solar energy, its uses, limitations and benefits
• Students will learn about solar energy through an inquirybased learning approach, handson learning, and reflection
Teaching the lesson:
A. Introduction
• The teacher will review what solar energy is (energy obtained from the sun).
• Ask students what form solar energy has (Heat), and what solar energy is used for (electricity, heating, light, chemical energy in plants, etc.)
• Ask students to observe the solar fountain. Is this active or passive use of solar energy? (active)
• Where is the energy collected? How can you tell? (in the solar panel, because it is made of material which will absorb sunlight)
• What happens when part of the panel is covered? (the water should not spray as much, because energy to the pump has decreased with less solar power.)
· What happens when all of the panel is covered? (The fountain will not spray at all because no energy is entering the system.)
B. Explanation:
The solar fountain works by using a solar panel made up of PV cells to provide electrical energy to run a fountain pump. More sunlight reaching the solar panel results in more water being pumped by the fountain. Any decrease in the amount of solar energy to the panel results in less electrical energy available to power the pump.
C. Evaluation:
• Identify some benefits of solar power, as well as any problems you experienced while using it. (Benefits renewable, can provide large amounts of energy, does not pollute. Limits difficult to store, not consistent source, conversion not very efficient, weather, time of day, season all affect source.)
• Can students identify ways to make the solar fountain work better? (Have larger solar panel, position panel for maximum sunlight, place reflectors around panel, etc.) D. Closure:
• How is solar energy a renewable energy source?
• What are other applications of solar energy? What else have you seen solar energy used for? (calculators, radios, traffic lights, warning lights on streets and water bodies, etc.)
• What device is used to convert energy in the fountain, and what conversion occurs? (The solar panel, or PV panel; heat energy to kinetic energy of the water, also heat to electricity which powers fountain.)
TEKS:
(3.2) Scientific processes: The student uses scientific inquiry methods during field
and laboratory investigations
(B) collect information by observing and measuring
(C) analyze and interpret information to construct reasonable explanations from direct and indirect evidence. (3.5) The student knows that systems exist in the world
Student expectations (b) observe a simple system and describe the role of
various parts.
(4.5) Science concepts: The student knows that complex systems may not work if
some parts are removed.
Credit: The Elm Fork Education Center, the Texas State Energy Office Renewable Resources and Sustainability Program, and Jessica White